Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
  • G02C5/00—Constructions of non-optical parts
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
  • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D6/00—Heat treatment of ferrous alloys
  • C21D6/004—Heat treatment of ferrous alloys containing Cr and Ni
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D6/00—Heat treatment of ferrous alloys
  • C21D6/02—Hardening by precipitation

Definitions

• the invention relates to a spectacle frame with at least one frame part which is made of chrome nickel steel and is produced by cold-forming.
• Chrome nickel steels are used in the spectacle industry especially for producing frame parts made of wire.
• the conventional, stainless spring steel wires offer the advantage of high strength, but cannot be used for the cold-forming of frame parts. Moreover, they offer a negative thermal stability, which is especially disadvantageous during soldering.
• chrome nickel steel is used for stamping frame parts. Such chrome nickel steel allows cold-forming, but it is linked to a comparatively high hardening, so that frequent intermediate annealing is necessary. The high hardening leads to a high stress on the stamping and punching tools. Concerning the thermal stability there are similarly unfavorable conditions as in spring steel.
• chrome steel is known which is usually supplied as pre-hardened and pre-tempered sheet metal and is used for making frame parts.
• chrome nickel steel shows a high resistance to corrosion and can achieve high strength through hardening
• parts for spectacles made of such chrome nickel steel can only be produced within limits because the thermal treatment of the chrome nickel steel in connection with the soldering entails at least in sections the loss of the strength previously achieved by hardening, which strength can subsequently no longer be reproduced by renewed hardening because the necessary thermal treatment would exceed the ability of the soldered connection to withstand the thermal stress.
• the invention is thus based on the object of providing a spectacle frame of the kind mentioned above in such a way that the cold-formed frame parts are joined with each other by means of soldered connections or can be connected to other frame parts.
• the invention achieves this object in such a way that the frame part consists of a chrome nickel steel with a minimum strength of 950 MPa.
• the precondition for the soldering of the cold-formed frame parts is created by using a chrome nickel steel of a minimum strength of 950 MPa without having to fear the loss of the required dimensional stability because said dimensional stability, which is given by the minimum strength of the chrome nickel steel, cannot be fallen below by a thermal treatment.
• the chosen magnitude of minimum strength of chrome nickel steel which can be set by respective alloy additives primarily depends on the stress imposed by the tools used for the cold-forming of the frame parts. Since the precondition for a high inherent strength of the cold-formed frame parts is improved with a higher minimum strength of the chrome nickel steel on the one hand, and the stress imposed by the tools is increased on the other hand, respective limits are imposed on the increase of the minimum strength of the chrome nickel steel used for the production of frame parts, although practice has shown that with increasing minimum strength the increase in strength by cold-forming will be lower, which allows higher forming degrees without intermediate annealing. If the minimum strength of chrome nickel steel for frame parts of spectacles is increased from 1000 to 1050 MPa, sufficiently economic production conditions for the frame parts in accordance with the invention can be ensured with a respective configuration of the tools.
• Chrome nickel steel with a minimum strength of 950 MPa can have a different composition.
• Especially advantageous chrome nickel steel can contain for example 0.05 percent by weight of carbon, 17 percent by weight of chromium, 4 percent by weight of nickel, 3.5 percent by weight of copper, 0.3 percent by weight of niobium.
• Such chrome nickel steel can be subjected to precipitation-hardening at temperatures which do not endanger the soldered connections of the frame parts made from such chrome nickel steel, so that the spectacle frames can be brought to the desired strength by precipitation-hardening after the soldering.
• the frame parts can be provided with smaller dimensions.

Landscapes

• Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Ophthalmology & Optometry (AREA)
• Optics & Photonics (AREA)
• Eyeglasses (AREA)

Applications Claiming Priority (3)

Publications (2)

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Citations (7)

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• 2001
  • 2001-12-19 AT AT0198401A patent/AT410986B/de not_active IP Right Cessation
• 2002
  • 2002-11-06 CA CA002470258A patent/CA2470258C/en not_active Expired - Fee Related
  • 2002-11-06 JP JP2003553319A patent/JP2005513525A/ja active Pending
  • 2002-11-06 AU AU2002357941A patent/AU2002357941B2/en not_active Ceased
  • 2002-11-06 CN CNB028254597A patent/CN100340897C/zh not_active Expired - Fee Related
  • 2002-11-06 US US10/498,538 patent/US6905204B2/en not_active Expired - Fee Related
  • 2002-11-06 WO PCT/AT2002/000311 patent/WO2003052490A1/de not_active Ceased
  • 2002-11-06 EP EP02791574A patent/EP1456709A1/de not_active Ceased

Patent Citations (8)

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